Polar Bear Controversy

The Polar Bear (Ursus maritimus) is a bear native largely within the Arctic Circle encircling the Arctic Ocean, its surrounding seas and land masses. Although it is closely related to the Brown Bear, it has evolved to occupy a narrower ecological forte, with many body characteristics adapted for cold temperatures, for moving across snow, ice, and open water, and for hunting the seals which make up most of its diet. Though there are many theories surrounding evolution, the two stand outstanding hypotheses applying to the modification from Brown Bear to Polar Bear are Lamarck’s theory of Use and Disuse, and Darwin’s theory of Natural Selection. The intention of this paper is to compare these thesis and determine the most appropriate in

The white phased black bear was said to have traversed barriers of the sea during the last ice age when glaciers covered most of northwest British Columbia. When temperatures started to rise, and glaciers started to retreat it is believed that the white bear was then isolated on the islands off the coast of BC. The white coats would suggest an adaptation to the white snow for hunting, however if that was the case, the evolutionary trail should have left the recessive gene behind when it was no longer useful to them in the temperate forests. Most research that is done on the Spirit bear is to try and understand the polymorphism of this species and how it has come to last among a low frequency in a minute area. Evidence now suggest that the reason for the white fur is actually a very important adaptation for the bear and is still very useful even in the array of

The bear have evolved along time ago and now there is only eight species existing. They evolved from early canids during the late Oligocene and early Miocene, about 25 million years ago. The earliest ancestors where the Dormaalocyon Latouri. An intermediate ancestor was the short faced bear, very similar to the modern day bear. It lived through the pleistocene period. It grew to thirteen feet long and was a herbivore. The ancestors to the modern day bears lived in the same climate and ate the same things. The modern bear contrast from the ancestor because the ancestor was more skinny and was smaller, and it was more cat like. The eight species of bear that still exist. They are the Polar bear, Brown bear, American black bear, Asian

Grizzly bears have had to adapt when the weather is off like having a warm winter it sets their internal clock off to where when they should be hibernating they are still out or cold weather comes late they are already awake from hibernation or cold weather comes to to early and they aren’t hibernating. They also have to deal with man made disasters like oil spills or fires, both can kill bears and kill what they eat like fish which could then kill the bears if they can not eat enough food because their immune system will deteriorate and kill them. Grizzly Bears are divergent because recent studies have shown that some grizzly bear’s mothers are polar bears and fathers are grizzly bears. This means that the fathers travel long distances to mate with mother polar bears. The most recent studies have suggested that they have been divergent from about 150,000 years ago. (Tia Ghose) Past research revealed that brown bears on ABC Islands, off the southeastern coast of Alaska, had mitochondrial DNA that look just like polar bear DNA.(Mitochondrial DNA comes only from the mother and is carried in the cytoplasm in the cell’s energy-making structures called mitochondria.) (Tia

It was in Eurasia, within 500,000 years ago, that brown bears roamed the land. It was a time when Eurasia was found coated in ice and the Arctic ocean became it. A pack of brown bears were forced to separate for the hunt for food. It is believed that glaciers forced isolation upon the packs resulting in the deaths of many bears. Isolation was an important part of the evolution between the two bears as it forced those with an evolutionary advantage, such as the colour and thickness of their coats, to enhance these advantages and managed to survive and breed. Unlike those who were unable to cope with the environment. This generation then made new adaptations to further increase their likelihood of survival in the polar environment (PBS, 2015). For example, the bears required differently shaped teeth. As seen in the picture below, the back teeth of a polar bear are less in number and size. However, it is clear that the front teeth are larger and sharper. This is because of the change in environment forcing a change in diet for the bears; instead of eating berries the bears had to consume seals and needed sharper teeth to tear through skin. In order to camouflage themselves the bears, overtime, grew white fur to blend in with the snow. Another adaption made the these bears is the hunting technique used; at first only seal carcasses that had washed ashore were eaten by them however over time the bears

The Miller's Tale" is the story of a carpenter, his lovely wife, and the two clerks (students) who are eager to get her into bed. The carpenter, John, lives in Oxford with his much younger wife, Alisoun, who is something of a local beauty. To make a bit of extra money, John rents out a room in his house to a poor but clever scholar named Nicholas, who has taken a liking to Alisoun. Another scholar in the town, Absolon the parish clerk, also has his eye on Alisoun.

The polar bear, the largest land carnivore in North America, one of the largest animals in the world and a favorite at zoos worldwide, has, over the years, adapted to its harsh Arctic environment. The appropriately named ‘ursus maritimum’ or sea bear usually lives between 15 and 18 years in the wild and spends most of its life on ice. It is the most recent of the eight bear species. The first polar bear was a brown bear subspecies, with brown bear dimensions and brown bear teeth. The polar bear evolution was rapid due to the small population and extreme pressure to survive. Even today, the polar bear continues to evolve to better adapt to the harsh realities of Arctic life.

The article “Love in the time of climate change: Grizzlies and Polar bears now mating” explains some of the effects of climate change on bears. Now this days more and more pizzlies or grolars, mixed of the Polar and Grizzly bears are seen in parts of Alaska and Western Canada. The bears are mating with other possible kinds of bears rather than not mating at all. Both of this bears are mating because this two different kind shares some similarity and shares same branches of their evolutionary tree. The polar-grizzly crossbreed is one of the most recent hybrid along with coywolf, a mix of coyote-dog-wolf, and a lynx bobcat. This mix breeds have been spotted

It is believed the Polar bears that walk the earth today, had descended from brown bears. This occurred through geographical isolation due to glacial drift in an area close to Siberia. They had undergone a rapid evolution, with changes that enabled them to adapt and survive in an Arctic habitat.

The principal cause of all the Human-Grizzly Bear conflict is human population growth. Human population has been increasing exponentially and humans are essentially invading natural environments in which animals like Grizzly Bears thrive. Habitat space for Grizzly bears is decreasing and they are competing for food and space with humans. Habitat destruction by humans leads to urbanization of natural habitats of animals; thus, leaving Grizzly bears to fend for themselves with scarce resources (Mace & Waller, 1998). Urbanization such as road development leads to fragmentation and increasing the chances Grizzly bear interaction with a human, this is because of transport and service corridors, particularly roads, are currently the prime form of humans to access to Grizzly bear range (MacHutchon and Proctor, 2015).

It’s possible that the polar bear-like DNA actually comes from a living mammal—perhaps a brown bear—that happened to pick up a few mutations that created a false resemblance to that ancient polar bear DNA.

Depending on the fossil record and DNA examination, researchers have possessed the capacity to land at a clearer photo of the polar bear's transformative way throughout the centuries. Somewhere in the range of 200,000 years back, when ice sheets secured quite a bit of Eurasia, the Arctic Ocean was totally solidified. It was amid this testing period that cocoa bears started to meander looking for sustenance. Roughly 125,000 years prior a populace of chestnut bears in the most distant north of their range was likely separated from their cocoa bear progenitors, maybe in view of rivalry for nourishment. The populace likely got to be confined by enormous icy masses and, while most passed on in the unforgiving environment, those holds on for a developmental

Everyone needs to become aware of the problems Global Warming causes, and they need to start putting that information towards preventing endangered species, like the polar bear, from becoming extinct. Polar Bears have been living for 600,000 years, but now there are only 20,000 polar bears left. Polar bears are a large marine mammal

They argue that polar bears will survive or evolve. An argument is that their only predator is man, however, they will come into competition with the grizzly bear and not be able to survive. Another counter claim is that the polar bears will evolve and adapt to their environments. Regardless of this, UCLA Biologists say, “To people who say polar bears can just change their diet, we are saying they WILL change their diet -- they will have to -- but it probably won’t be sufficient for them.” Even if the polar bear evolves to fit their environment, it will not be adequate, especially with their competition with the grizzlies.

The polar bear lives up in the Arctic region where global warming and climate change are melting the ice caps that the bears thrive on. They use the ice as a platform from hunting and rest. The random pocket holes in the ice, where the seals pop up at, is where the polar bear catches its prey. With this reduction of ice, “the abundance of seals, and increases the amount of energy and time needed for hunting, leaving less energy for reproduction” (Endangered Species and Habitats).